1. Field of Invention
The present invention relates to height adjusting mechanism for a chair which stands between a seat and legs of a chair. Furthermore, the present invention is about adjusting height of a chair simply and easily by operating a button which is attached at the arm of a chair. In the height adjusting mechanism for a chair, cable actuator is installed to adjust the height and the button is included in the cable actuator.
2. Description of the Background Art
In the conventional height adjusting mechanism for a chair, a spindle guide 500 is inserted and fixed inside a cylindrical outer tube 600 and a spindle 50 which moves up and down while contacting the inner side of the spindle guide 500 is installed as shown in FIG. 1 which is a vertical cross sectional view. A Gas chamber 30 is included inside the spindle 50 and a piston 11 which engages in piston movement according to the pressure of gas is inserted inside the gas chamber 30. The gas chamber 30 is divided into a first gas chamber 30a and a second gas chamber 30b along the boundary of the piston 11. The piston 11 is connected to a piston rod 110 which penetrates the second gas chamber 30b and one end of the piston rod 110 is fixed to the cylindrical outer tube 600 with a fixing clip 235. A resilience member 620 is inserted at a lower end of the piston rod 110 in order to absorb shock on the outer tube 600 put by the lower end of the piston rod 110 when the spindle 50 moves up and down due to the movement of the piston and to maintain certain resilience. A ball bearing 52 is sandwiched in between bearing support 42 and 44 inserted at a lower end of the resilience member 620. A movement preventing jaw 35 is formed at a lower end of the piston rod 110 in order to prevent the bearing support 42, 44 and the ball bearing 52 from moving up towards upper part of the piston rod 110. As the resilience member and the ball bearing are inserted in the piston rod, shock put on the spindle 50 is absorbed and rotation frictional force of the spindle 50 is reduced.
An opening/closing pin holder 400 which is made of sealing member is mounted outside the first gas chamber 30a and the opening/closing pin 120 which can discharge or block gas of the first gas chamber 30a is mounted on an opening/closing pin holder 400. Projected end of the opening/closing pin 120 is formed to contact a push button 33 which is attached at an end of the spindle 50. A gas moving valve 160 is formed at an outer wall of a gas chamber 30 so that the first gas chamber 30a and second gas chamber 30b can move along by the operation of the opening/closing pin 120. In addition, a plurality of O-rings 608 are inserted outside the piston 11 and the opening/closing pin holder 400 in order to maintain sealing and prevent gas inside cylinder from leaking.
In the conventional height adjusting mechanism for a chair structured as described above, height of a chair is adjusted as gas inside the first gas chamber 30a and the second gas chamber 30bmoves back and forth the two chambers through the gas moving valve 160 as the entrance of the first gas chamber 30a which is blocked by the opening/closing pin 120 is opened by pushing the push button 33 which is located at an end of the spindle 50 and as the spindle 50 moves according to the movement of the gas. In order to maintain the height of a chair, simply let the opening/closing pin 120 block the entrance of the first gas chamber.
In the conventional height adjusting mechanism for a chair, an extra operating lever 88 needs to be installed at the lower part of a chair to push the push button 33 as the push button 33 is attached at the lower part of the spindle 50 as shown in FIG. 2. Therefore, in order to adjust the height in a chair manufactured with the conventional method, a person sitting on the chair has to bend over to operate the lever which results in inconvenience in operating the lever and unpleasant outlook due to the projected lever.